Who built this site?

What did this site do?

The creators of this site associated latitudes and longitudes to the images in
the San Francisco Historical Photograph Collection. This process is known as geocoding. Doing this
allows the images to be placed at points on a map, which enables new ways of
exploring this collection.

How were they geocoded?

The geocodes are based on two sources:

Photo Subjects. All photographs in the “City Hall (old)”
series presumably belong in the same place. We manually geocoded several
hundred subjects.

Addresses and Cross-Streets. The photo descriptions often contain
either an address, block number or set of cross-streets. These were
converted to coordinates using the Google
Geocoding API.

What's the story of this project?

Several years ago, @danvdk searched for his cross-streets
on the Library's San Francisco Historical Photograph Collection and found the
photo on the right. The image was mislabeled — the intersection in the
foreground is actually Waller and Fillmore, not Waller and Webster. Which
meant that this photo from 1945 was taken from his roof!

He put together a now-and-then
shot, but it always bothered him that the mislabeling of the image was so
crucial to my finding it. This led to the idea of putting the images on a
map.

And now, years later, we have that map!

What fraction of the images have been geocoded?

The library's collection contains about 40,000 images. Many of these
photographs have little geographic context (e.g. they're portraits) and
cannot be located. In all, about 20,000 of the images could be placed on a
map. We've geocoded about 65% of the possible images: 13,000.

How can you help?

If you're technically minded, here's a JSON file containing all the image
descriptions, as well as geocodes for the records on the map (including the
reason we thought they were at that location): records.js.zip (2MB download). If you improve
on my geocoding or do something else interesting with the data, please share
your results!